Mercedes-Benz GLB-Class vs Subaru Outback: Specs Compared

Also searched as Subaru Outback vs Mercedes-Benz GLB-Class specs — both orientations show this same side-by-side comparison.

The Subaru Outback is the more efficient of the two: it reaches 29 mpg combined versus 28 mpg for the Mercedes-Benz GLB-Class, a 1 mpg advantage and costs about $600 less per year to fuel.

Across 4 measured categories, the Subaru Outback leads in 4. Figures are EPA test data, not manufacturer claims.

2020–2026

Mercedes-Benz GLB-Class

Small Sport Utility Vehicle 4WD · 20 configurations

28mpg combined (best)
All Mercedes-Benz GLB-Class specs

2018–2027

Subaru Outback

Small Sport Utility Vehicle 4WD · 26 configurations

29mpg combined (best)
All Subaru Outback specs

Head-to-head specifications

MetricMercedes-Benz GLB-ClassSubaru Outback
Best combined MPG28 mpg29 mpg ✓
Best city MPG25 mpg26 mpg ✓
Best highway MPG33 mpg33 mpg
Lowest annual fuel costEPA estimate at 15,000 miles per year$2,700$2,100 ✓
Lowest CO2 output311 g/mi308 g/mi ✓
Engines offeredSIDI; Mild Hybrid, SIDISIDI, 2.5, 3.6
TransmissionsAutomatic (AM8)Automatic (AV-S8), Automatic (AV-S7), Automatic (AV-S6)
DrivetrainsFront-Wheel Drive, All-Wheel Drive, 4-Wheel DriveAll-Wheel Drive
Fuel typesPremiumRegular
EPA classSmall Sport Utility Vehicle 4WDSmall Sport Utility Vehicle 4WD
Years covered2020–20262018–2027
Configurations on record2026

Source: EPA fuel economy records via fueleconomy.gov. Best-case values across all recorded configurations for each model.

Mercedes-Benz GLB-Class vs Subaru Outback dimensions and size

The Subaru Outback is 9.4 inches longer than the Mercedes-Benz GLB-Class on a wheelbase 3.1 inches shorter, and 207.2 lbs heavier. Both clear the roughly 200 inches of usable length in a standard single garage bay.

Mercedes-Benz GLB-Class versus Subaru Outback exterior dimensions
DimensionMercedes-Benz GLB-Class (2026)Subaru Outback (2026)Difference
Length182.3 in191.7 in9.4 in
Width (excl. mirrors)72 in74 in2 in
Height66.5 in67.3 in0.8 in
Wheelbase111.4 in108.3 in3.1 in
Curb weight3,759 lbs3,966 lbs207 lbs

Width excludes mirrors; add 8–12 inches for mirrors out. Figures are for the newest model year on record for each vehicle. See both drawn to scale.

Mercedes-Benz GLB-Class vs Subaru Outback: what the numbers mean

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Subaru Outback burns about $2,100 of fuel annually against $2,700 for the Mercedes-Benz GLB-Class. That $600 yearly gap compounds to roughly $3,000 over five years and $4,800 over eight — often more than the price difference between two trims of the same vehicle, and the single largest running-cost line item separating these two.

City and highway economy: the Subaru Outback leads in both cycles — 26 mpg city and 33 mpg highway against 25 and 33 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.

Powertrain choice: the Mercedes-Benz GLB-Class is recorded with 2 distinct engine configurations (SIDI; Mild Hybrid, SIDI), the Subaru Outback with 3 (SIDI, 2.5, 3.6). Across 20 recorded Mercedes-Benz GLB-Class configurations and 26 for the Subaru Outback, the wider the engine spread the more the real-world fuel efficiency depends on which version you actually buy, so check the specific model year and drivetrain rather than the headline number.

Drivetrain and class: the Mercedes-Benz GLB-Class is offered with Front-Wheel Drive, All-Wheel Drive, 4-Wheel Drive, the Subaru Outback with All-Wheel Drive. All-wheel drive typically costs one to two mpg combined against the same vehicle in front- or rear-wheel drive, which is worth remembering when the gap between these two is small. The EPA classes them as Small Sport Utility Vehicle 4WD and Small Sport Utility Vehicle 4WD respectively — the class drives the interior volume, cargo space and passenger space each one is measured against.

Tailpipe emissions: at their cleanest configurations the Subaru Outback emits 308 g/mile of CO2 versus 311 g/mile for the Mercedes-Benz GLB-Class. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.

GLB-Class vs Outback: common questions

Which is better on gas, the Mercedes-Benz GLB-Class or the Subaru Outback?

The Subaru Outback is the more efficient of the two: it reaches 29 mpg combined versus 28 mpg for the Mercedes-Benz GLB-Class, a 1 mpg advantage and costs about $600 less per year to fuel.

Which costs less to run per year?

By EPA estimates at 15,000 miles a year, the Subaru Outback runs about $2,100 a year in fuel at its most efficient configuration, versus about $2,700 for the Mercedes-Benz GLB-Class — a difference of roughly $600 per year.

What engines do the GLB-Class and Outback offer?

Mercedes-Benz GLB-Class: SIDI; Mild Hybrid, SIDI. Subaru Outback: SIDI, 2.5, 3.6.

Are they in the same vehicle class?

Yes — the EPA classifies both the Mercedes-Benz GLB-Class and the Subaru Outback as Small Sport Utility Vehicle 4WD, so they compete directly.

More GLB-Class comparisons

More Outback comparisons

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